1. Field of the Invention
The present invention relates to a traffic control system. More particularly, the present invention relates to the use of geometric and mathematic shapes or light color combinations, to make traffic control signals easier to read for persons who are red/green color blind or who are otherwise challenged or handicapped in their ability to distinguish certain colors.
2. State of the Art
In virtually all cities having more than a few hundred residents, it is common to have one or more traffic signals to indicate to a driver when he can proceed through an intersection and when he must stop. The most common arrangement for such traffic signals is to have a red light, a yellow light, and a green light. In a typical configuration, the red light is disposed on top, the yellow light in the middle, and the green light at the bottom.
In addition to such configurations, there are also numerous other configurations in which the lights are disposed in a horizontal array or in which a plurality of lights are used to signal that a driver may or may not turn during a given period of time. Furthermore, some locations use a single light which changes color depending on whether the driver is allowed to proceed.
For most individuals, the use of red, yellow, and green lights is very convenient. The color contrast between the colors clearly warns the driver of what he may or may not do. Even less common arrays of light, such as horizontally disposed arrays or arrays having color turn arrows are highly practical for most drivers.
There are, however, a large number of drivers for which the current signal system is frustrating and even dangerous. Millions of people around the world suffer from red/green color blindness. Such individuals have a difficulty or even a complete inability, to distinguish between the colors red and green. Thus, such individuals are unable, from the color, to determine whether they are being instructed to stop or to proceed.
Many with red/green color blindness compensate for the inability to distinguish between the stop and go signals by locating the position of the illuminated light. Thus, the driver may notice that the light is in the top circle thereby indicating stop, as opposed to being at the bottom and indicating that it is appropriate to proceed. When driving, this causes the driver to keep his eyes off the road for a longer then normal time to determine if it is permissible to proceed. Of course, drawing the driver's eyes off the road increases the risk that he might run into a car in front of his vehicle.
Even when the driver is stopped at an intersection, the inability to distinguish the two colors can raise problems. Unless the driver keeps his or her eyes focused on the light during the entire time waiting at an intersection, it takes a second or two for the driver to locate the signal and determine the location of the light. At night and other low ambient light conditions, it is very difficult to ascertain the locations of other non-lit signal lights. Thus, it can be very difficult to use the position method to verify red or green lights. The delay caused by trying to figure out the light position is often enough to cause embarrassment as drivers behind may begin honking if the light is green. This simply compounds the frustration and emotionally impacts the driver's decision making process. Additionally, if the driver makes a mistake, he or she may very well proceed through a red light mistakenly believing that the light is green.
These problems are significantly compounded, however, when a driver faces an unfamiliar light pattern. For example, in some locations having severe weather or height restrictions, the red, yellow, and green lights are disposed in a horizontal array on an overhead post, rather than in a vertical orientation. Thus, the red light may be on the far left and the green on the far right. However, if the driver is unfamiliar with the particular array, he or she is forced to guess as to wether it is the red or green light that is being illuminated, even if the driver can determine the position of the illuminated light. Thus, it is not uncommon to hear stories of color blind people who have traveled through an entire town passing through every red light, mistakenly believing that the light was green. Likewise, if the signal has multiple lights for indicating turning directions, a color blind driver may be unable to determine whether the signal or lighted arrow is red or green. Thus, the driver could turn in front of oncoming traffic causing a potentially fatal collision.
The effects of color blindness are even further exacerbated if the green light used is a color similar to lime green on the spectrum. To many red/green color blind people, lime green appears the same as the color yellow, because they only see the yellow portion of the yellow-green light. Thus, the driver may stop at an intersection when the light is green believing that the light has changed to yellow and that a red light is imminent. Of course, suddenly stopping at an intersection is both illegal and is likely to cause an accident.
Even if a red/green color blind or otherwise color challenged individual is able to determine which indication is being given, the additional challenge of determining location adds additional stress and time to the driver's decision making process, slowing down reaction time. This is particularly difficult where the driver is attempting to find his or her way in an unfamiliar city with unfamiliar traffic light orientations. If the driver turns to look at street markings, etc., he must reorient himself every few seconds to determine if a red light has changed to green, or vice versa.
Thus, there is a need for a traffic control system which enables people suffering from color blindness (or other vision problems) to readily determine if a signal indicates to proceed or stop without being able to determine the color of the light. Such a system should be easy to use and not interfere with the driving habits of those who do not suffer from red/green color blindness.